Filter for coffee makers



Sept. 27,1949. RElCHOLD 2,483,104

FILTER FOR COFFEE MAKERS v File'd March 28, 1945 Snventor L UD w/G fPfS/c/7/0-Lz7.v

Gttorneg Patented Sept. 27, 1949 UNITED STATES ATENTl GFFICE FILTER FOR COFFEE MAKERS ration of Connecticut Application March 28, 1945, Serial No. 585,276

This invention relates to lters for coffee makers and more particularly for coffee makers of the vacuum type which generally comprise a lower bowl having an upper bowl mounted thereon with a stem depending from the upper into the lower bowl. The filter, for which my invention is intended, is positioned above said stem.

When water is heated in the lower bowl, it is forced upwardly through the stem into the upper bowl where it is infused with coffee grounds therein. The lower bowl is then permitted to cool and a vacuum is created therein which will draw the infusion from the upper bowl back into the lower bowl; the filter serving to filter the resulting brew by preventing the coffee grounds from passing into the lower bowl with the liquid.

Although `various types of such filters have been produced, it has been'found that those which are secured in position and retained therein by suitable spring means are the most desirable since they produce more uniform results through their operation and the coffee is of a uniform quality.

The spring for retaining said lter in position is usually anchored to the bottom of the stern of the upper bowl and since different models of coffee makers have stems of different lengths, it is desired that a spring be provided which can be adjusted for the different length stems without unduly changing the tension of the spring.

It is an object of this invention, therefore, to provide a coffee maker lter having novel and eiicient means for adjusting the anchoring spring thereof to accommodate upper bowl stems of different lengths.

A further object of this invention is to provide a novel filter which can be used with or without a cloth strainer.

Further objects and advantages of this invention will be more clearly understood from the following description and accompanying drawings in which:

Fig. 1 is a view in central Vertical section showing an upper bowl of a colee nfaker with my improved filter attached thereto.

Fig. 2 is a plan View of said filter.

Fig. 3 is a side elevational view thereof.

Fig. 4 is a bottom View of the filter disc.

Fig. 5 is a side view partly in vertical section showing the use of a cloth strainer over the iilter disc.

Fig. 6 is a side elevational view of the spring securing bar.

As shown in the drawings, the numeral 5 denotes an upper bowl such as used in conven- 3 Claims. (C1. 210-162) tional coifee makers of the vacuum type. The said bowls are usually provided with a stem B which depends from the bottom 1 thereof into a lower bowl, not shown. My improved filter may consist of a disc-shaped plate '8 having an annular bottom surface 9 preferably provided with radially extending ribs and serrations thereon. The top of said member is provided with a recess It and an aperture I2 extends from the bottom of the recess It through said disc. Radially extending grooves II are also provided in the top surface of said disc. The bottom of the disc-shaped member has an inverted recess i3 for the purpose to be hereinafter described.

An attachment bar I4 is slidably mounted in the disc 8 and extends downwardly therefrom through the aperture I2. The upper end of said bar is formed with a loop to provide a suitable handle and a washer I6 is provided below said loop to prevent the passage of :coffee grounds or sediment through the aperture |12.

The said bar` I4 has upper and a lower set of threads, or teeth I'I and I8, for engaging the coil spring I9 which depends from said bar I4 and has a hook 20 extending from the bottom thereof to engage the edge of the stem and thereby anchor the filter disc 3 in position so as to prevent the passage of coffee grounds from the upper bowl into the lower bowl, while still permitting the passage of liquid through the grooves in the surface 9.

The said spring is constructed with the proper tension to permit the disc to Vrise under pressure of the liquid, as it passes from the lower into the upper bowl, but to also firmly retain the filtering disc in position as the liquid is returning from the upper into the lower bowl.

As the said stems 6 vary in length for different makes and types of said coffee makers, it is desirable that the spring be adjustable on the bar I4 to accommodate the different lengths of stems without requiring a spring of undue length which would provide too little tension for the disc 8 when used on a short stem and too much tension when used on a long stem.

I therefore provide, on said spring I9, a p0rtion 2l consisting of a plurality of turns of lesser diameter than the body of the spring I9. The diameter of said portion 2l' being such that the turns thereof may be threaded to either of the series of teeth II or I8, depending upon whether the lter is to be used in an upper bowl having a long or short stem.

As illustrated in Fig. 1, the spring I9 is attached to the upper set of teeth I1 on the bar I4 to accommodate the short stem 6. In Fig. 3, the said spring is shown as being attached to the lower set of teeth I8 so as to accommodate a longer stem. It will be understood that, by simply turning the spring, the reduced portion 2l thereof may be threaded to either the Set of teeth i8 or the set I7, thereby rendering it possible to use 'a spring of :minimum length and still accommodate a wide variation of stem lengths without greatly changing the tension with which the lter disc 8 is retained against the bottom 'l of the coffee maker bowl 5.

As shown in dotted lines in Fig. 1, the bar I4 may be used as an extendablehandle, inlowering the disc 8 to its positionthrough -theopening in the top bowl 5, by simply grasping the loop l5, prior to placing the lter in the upper bowl, and permitting the said disc to slip downwardly on the bar i4 and rest upon the coil portion of the'spring. After the disc 8 has been placed upon the bottom of ythe bowl, vthe 4said handle is releasedfand the bar 'ifi will slide into its .normal position by gravity fand Vthe sp'ringmay -then ybe readily attached to the bottomfo'f the stem fbyy means of `the hooks 2B.

-As shown 'in Fig. 5, a cloth lstrainer 22 of conventionalorm fmay be placed over the lter disc 8 when it is desired to produce nished coffee that is of a .higher purity than that Ywhich can be produced through va'flter `without a cloth strainer. rEhe said strainer is placed over the stem so that it issupportedin 'thefcenterfby the loop l5 and filtration will take place through the material of said strainer between the lower surface 9 and the surface of the 'bottomf'lfioffthe bowl; thus preventing the passage of'evennne coifeegrounds or sediment with the coffee brew as it passes from the upper bowl into `the Ilower bowl 'of 'the coffee maker.

'.It' will be noted that the sets of teeth I1 and I8 arexspac'ed from yeach other. This is to permit changing of the Fspring from one position to another Ion the attachment bar I4 without requiring continued 'rotation of the spring, `I-Iowever, if closerra'djustment'is desired, the teeth may be continuous.

I-claim:

l.. For a coffee `vmaker `of "the 'character described 'having 'a stem depending therefrom, a fiterng rdevice I'comprising va disc-shaped member having an apertureextending therethrougn'a bar extending through said aperture .and slidably secured to said disc-shaped member, said iba-r having 'an abutment Tor vsecuring the same to said disc-shaped fmember, iteeth .in `the edge "of said bar, a wire spring for resiliently anchoring said member in iiltering position, a hook depending from the said spring for anchoring the same to the bottom of said stem, and a plurality of turns on said spring adapted to be engaged with said teeth for adjustably securing the spring to the bar to accommodate stems of different lengths.

2. For a coffee maker of the character described comprising a disc-'shaped member having an annular bottom surface with a series of grooves extending radially thereon and permitting filtration therethrough; the said member having a recess in the top thereof and an aperture extending vertically 'from said recess through said member, a `bar slidably extending through said recess, Ialhandle 'portion on said bar tting within said recess, .a springior anchoring said lter in position, and cooperating means on said spring and bar for adjustabl-y securing the spring to the bar.

3. A ltering device o'i the character described comprising a ltering member, a bar vertically slidable ,in and depending from said member, a coli spring for anchoring said device in operable position, and means for securing said spring to bar; said means Ycomprising spaced sets of teeth'projecting lfrom the edge oi said bar, and turns in said spring `oi lesser diameter than the remaining portion-of the spring and adapted to be thre to said teeth for adjustably securing the sprl at diierent distances from the ltering member and permitting free movement of said turns over Asaidbarbetween said sets of teeth.

LUDWIG REICHOLD.

REFERENCES CITED The following references are of record in the ille oi this patent:

narran Pamiers Number Name Date 1,006,886 Sptzig Oct. 24, 1911 v1,157,778 HemmingV et al Oct. 26, 1915 1,634,705 Bridges July 5, 1927 1,731,698 Anderson Oct. 15, 1929 1,967,983 Wolcott July 24, 1934 '72,234,678 Matson Mar. 11, i1941 2,236,254 Brault June 16, 1942 '2,370,674 Lucia Mar. 6, 1945 2,388,335 McCullough Nov. 6, 1945 FOREIGN PATENTS Number Country Date 401,322 'Great Britain Nov. 7, 1933 

